Field of the Invention
The present invention relates to a topboard support device for a grand piano, which is applied to a grand piano, for supporting a topboard, in an open state, which is mounted on the top of a piano body of the grand piano in a manner capable of being opened and closed.
Description of the Related Art
Conventionally, as the topboard support device for a grand piano, of the above-mentioned type, there is known one disclosed e.g. in Japanese Laid-Open Patent Publication (Kokai) No. 2012-208278. This topboard support device supports a topboard which is mounted on the top of a piano body in a manner capable of being opened and closed, using a topboard prop from below, and holds the topboard in an open state. Specifically, the topboard is mounted to a left portion of an outer rim in a manner pivotally movable about a horizontal axis, while the topboard prop is mounted to an inner surface of a right portion of the outer rim in a manner pivotally movable about the horizontal axis.
When the topboard closes the top of the piano body, the topboard is placed on an upper surface of the outer rim, in a horizontal posture. In this case, the topboard prop is accommodated below the topboard in a substantially horizontal posture in a manner crossing ribs each extending in a front-rear direction of a frame within the piano body, in a state partially placed on the ribs. On the other hand, when the topboard is opened, the topboard is pivotally moved upward, and also the topboard prop is also pivotally moved upward, whereafter a tip end portion of the topboard prop is brought into engagement with a receiving portion formed in a lower surface of the topboard. With this, by causing the topboard and the topboard prop to form a substantially right angle therebetween, the opened topboard is held in a stable state.
As described above, when the topboard closes the upper surface of the piano body, the topboard prop is accommodated in the state placed on the ribs of the frame. In this case, the upper surface of the outer rim is required to be set higher in position than the uppermost portion of the topboard prop accommodated in the state placed on the ribs of the frame, so as to avoid interference between the topboard and the topboard prop. For this reason, the dimension of height of the outer rim becomes relatively larger, and as a consequence, the thickness of the piano body is increased. This is against a demand of improving marketability of a grand piano by slimming down a piano body.